Objective To observe the effect of lowering intraocular pressure(IOP) treatment on ocular hemodynamics in patients with nonarteritic anterior ischemic optic neuropathy (NAION).Methods A total of 68 patients with NAION (68 eyes) were enrolled in this study.The patients were randomly divided into treatment group (38 eyes of 38 patients) and control group (30 eyes of 30 patients).All the patients were received methylprednisolone pulse therapy (200 mg,three days),vasodilator therapy with intravenous infusion of Xueshuantong solution (300 mg),optic nerve nutritional therapy with mouse nerve growth factor (30 μg) and acupoint injection in temporal with compound anisodine (2 ml).The total course was 10 days.The patients of treatment group received IOP lowering treatment to reduce the IOP to ≥ 8 mm Hg (1 mm Hg=0.133 kPa) or in a 30％ reduction.The patients of control group received no IOP lowering treatment.The peak systolic velocity (PSV),pulsatility index (PI) and resistance index (RI) of ophthalmic artery (OA),central retinal artery (CRA) and short posterior ciliary arteries (PCA) before and after treatment were comparatively analyzed by color doppler flow imaging.Results The differences of PSV (t=1.023,1.145,0.569),PI (t=0.679,0.956,1.634) and RI (t=0.816,1.657,0.998) of OA,CRA and PCA before treatment in treatment group and control group were not statistically significant (P＞ 0.05).Compared with before treatment,PSV (t=3.150,7.650,3.520) and PI (t=2.420,5.430,7.650) of OA,CRA and PCA increased obviously (P＜0.05),RI of OA,CRA and PCA decreased obviously (t=5.320,9.640,18.360; P＜0.05) after treatment in treatment group.In control group,the differences of PSV (t=2.090,-2.550,-2.100) and PI (t=-2.310,-2.230,-4.490) of OA,CRA and PCA between before and after treatment were not statistically significant (P＞0.05) ; but the differences of RI of OA,CRA and PCA between before and after treatment was statistically significant (t=2.970,2.160,2.690μ P＜0.05).Compared with control group,PSV (t=2.632,2.135,5.364) and PI (t=3.251,2.432,4.243) of OA,CRA and PCA increased obviously (P＜0.05),RI of OA,CRA and PCA decreased obviously (t=3.664,2.938,4.324; P＜0.05) after treatment in treatment group.Conclusion Lowering intraocular pressure treatment can improve the ocular hemodynamics in NAION patients.